1. Field of the Invention
The present invention relates to a display operation device for giving an instruction to electronic equipment and, more specifically, to a display device receiving a user instruction using a user interface (UI) component such as a software key as a trigger of some process, as well as to an image processing apparatus having such a display operation device.
2. Description of the Background Art
As one type of image processing apparatuses as electronic equipment, image forming apparatuses (typically, copy machines) are introduced to many places of business (companies and offices). A main function of an image forming apparatus is to form an image on a sheet of recording paper. Therefore, it is often the case that the image forming apparatus has a printer function, a copy function and the like. The image forming apparatuses are often connected to a network, to allow use by a plurality of users. A multifunction peripheral (MFP) has been known as one type of such image forming apparatuses. An MFP has a scanner function, and has a plurality of basic operational modes such as a copy mode, a facsimile mode (hereinafter “facsimile” may also be denoted as FAX), and a network-supported printer mode. It is expected that the scanner function will be used more frequently in the future in such image forming apparatuses. In the copy mode and facsimile mode also, it is possible to read an image using the scanner function and to set functions such as duplex (two-sided) printing, collective printing (such as 2-in-1 by which two pages of an original document are printed on one sheet, or 4-in-1 by which four pages of an original document are printed on one sheet), and enlargement or reduction of size.
When using such an image forming apparatus, by way of example, the user makes the following operations. First, the user has image data read by the image forming apparatus in the scanner mode. Thereafter, the user inputs various instructions through an operation panel, and performs image processing (such as collection). Then, the user gives an instruction to start a final processing of the image (printing to a sheet of paper, transmission by facsimile, and saving as a file). A screen image allowing setting of functions in various operational modes, for example, is displayed on the operation panel. Therefore, it is possible for the user to easily set various functions.
Recently, a touch-panel display comes to be increasingly used as such an operation panel. A touch-panel display includes a liquid crystal panel (display panel) and a touch-panel stacked on the liquid crystal panel. Typically, items (software keys) allowing selection of an operational mode of the image forming apparatus are displayed on the touch-panel display. Viewing the display, the user presses a position where a desired item is displayed, on the touch-panel display. For the user, it seems as if he/she has pressed a software key. Information related to which position has been pressed is transmitted to a computer controlling the image forming apparatus, and what operation is to be carried out is determined in accordance with the position, by a program running on the computer.
The touch-panel display provides both the display function and the operation function. It is advantageous in that it occupies a smaller area for installation than a display unit and an operation unit provided separately, it allows various and many manners of display, and it provides various and many functions.
By way of example, when an MFP having a touch-panel display as such as an operation panel is in the copy mode, a copy start key (button) is displayed on the display as an initial screen image. If the copy start key is pressed, using this as a trigger, the MFP automatically reads a document placed on an automatic document reader and forms a copy on a sheet of recording paper.
After the start of copying, it may be desired to stop copying by some reason. For this purpose, it is a general practice to display a copy stop key together with the copy start key, so that copying can by stopped by pressing the copy stop key once the copying operation is started. However, displaying the copy stop key together with the copy start key hinders efficient use of the area of touch-panel display. Considering the fact that MFPs come to have various and many functions, many pieces of information must be displayed on the display, and such pieces of information must be displayed in an easily viewable and easily understandable manner. Therefore, the area of touch-panel display should not be wasted.
In order to solve such a problem, Japanese Utility Model Laying-Open Application No. 59-58457 (hereinafter referred to as '457 Reference), which will be described later, discloses a technique of using one switch both as a copy start switch and a copy stop switch. Specifically, '457 Reference discloses a technique in which during a copy operation, the copy start key is used as a copy stop key. In the device disclosed in this reference, either one of two character strings “START” and “STOP” lights up on a hardware key. The character string corresponding to the usable function lights up on the key.
On the other hand, in the MFP, various problems may occur in connection with so-called supplies, including paper-out, toner-out and paper jam. Japanese Patent Laying-Open No. 59-140463 (hereinafter referred to as '463 Reference) discloses a copy function operation device, in which a plurality of icons representing the state of copying machine (such as paper-out, toner-out and paper jam) at the time of copying, on a copy start button for starting copying.
The technique described in '457 Reference and the technique described in '463 Reference are based on similar ideas of allocating different functions to one key or button and switching the functions to be used. These are good techniques that allow advantageous use of the display area.
These techniques, however, still have room for improvement, in connection with the MFP using a touch-panel as described above as an operating device. It is often the case that keys for instructing execution of various and many functions are displayed on the touch-panel. In such an MFP, introduction of the technique disclosed in '457 and '463 References may lead to the following problem, Specifically, in such an MFP, execution instruction key is provided for each of the plurality of functions. Then, combination of a position where a key instructing execution of a function is displayed and a position where a key for executing a process related to the key are displayed, or a position where a piece of information related to the key is displayed becomes complicated. Consequently, if problems occur, it could be difficult for the user to respond quickly to solve the problem,